In traditional art, a mobile terminal is usually configured with multiple keys. Each key corresponds to a preset input instruction, and a user can trigger an input instruction by pressing a key. When there are so many preset input instructions that the keys are not enough, an input instruction can be triggered by using a key combination. However, for a mobile terminal with a touch screen, e.g., a smart phone, an input instruction can be triggered by obtaining a pressing or sliding operation of the user on a certain area of the touch screen.
However, since generally a mobile terminal is designed to be relatively light and with a relatively small size, and keys configured in an input area thereof usually are relatively small, when a user selects a key to trigger an instruction, he is easy to press a wrong key to cause an input failure, and needs to input it again. While for a mobile terminal with a touch screen, a user needs to first position a virtual key (an icon) on the touch screen with naked eyes and then trigger an instruction by press. Therefore, the methods for triggering an instruction in the traditional art are not convenient enough.